The present invention relates to a method of operating a door drive which includes at least one high-speed mode and at least one normal-speed mode. The present invention also relates to such door drive with a corresponding control.
In the high-speed mode of these so-called high-speed drives, the door usually is opened at a higher speed and is closed at normal speed. In the normal mode, however, the door is moved at normal speed both when opening and when closing. Such high-speed drives are used in particular for rolling, revolving or sliding doors, and furthermore in particular for industrial doors, garage doors and/or courtyard doors.
The higher speed in the high-speed mode exerts great load on the door drive, whereas the lower speed in the normal mode saves the drive. To avoid an overload of the door drive, known door drives therefore usually are designed such that within a certain time interval only a firmly specified number of door operating cycles can be performed at the maximum speed. For instance, the drive maximally opens twice at high speed, whereas the succeeding cycles only are possible at normal speed. This limitation of the high-speed cycles also can refer to a period of e.g. 10, 30 or 60 minutes.
What is problematic with this drive is the fact that the high-speed function is not optimally available. The rigid control, which only considers the number of cycles within a certain fixed time interval, also prevents an operation in the high-speed mode when the door drive actually is not subjected to a great load after the admissible number of high-speed cycles, e.g. because the door runs very smoothly, and therefore could still be operated in the high-speed mode without the risk of an overload.